Validate a domain name or ip addres using regex

Question

this is the code I use but I can't set EXP2 to limit the number under the 256. Does anybody help?
P.S.
EXP1 validate a domain name (es. www.myserver.com)
EXP2 may validate IP address (es. 111.111.111.0)
public static boolean isServerAddress(String s){
    System.out.print(s + " ");     
    String EXP1 ="([a-zA-Z0-9]+).([a-zA-Z0-9]+).([a-zA-Z]{2,3})|([a-zA-Z0-9]+).([a-zA-Z0-9]+).([a-zA-Z]{2,3}).([a-zA-Z]{2,3}+)";
    String EXP2 ="([0-9]{1,3}+).([0-9]{1,3}+).([0-9]{1,3}+).([0-9]{1,3})";
    if(Pattern.matches(EXP1, s)){
      return true;
    }else if(Pattern.matches(EXP2, s)){
      return true;
    }else{
      return false;
  }

Answer 1

This regex should work for your.
Make sure you look at it and understand why it works. Also, you use '.' in your regular expressions. A period will match any character, yso you must escape your periods if you want to match the period character.
String BYTE_EXP = "(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])";
String EXP2 = BYTE_EXP + "\\." + BYTE_EXP + "\\." + BYTE_EXP + "\\." + BYTE_EXP;